Smart Phone Light Meter App

There seem to be a few of these. I want to use one with my film cameras to give me a record of location and exposure (which I will set on the camera) as a sort of Exif data for film.Any experiences/ideas?

In this week's AP they do quick reviews of 6 hand-held meters, one of which is Light Meter for Android, and I believe iOS as well. It is free, with adverts, but fortunately the ads are not intrusive, like some other free apps. They run at the top of the screen above the meter itself. AP said it was remarkably accurate.

Yesterday evening I downloaded it to my ageing Galaxy SII and it works a treat. It looks a little like an old Zeiss Ikophot, being yellow/gold in colour, although the meter reading itself is more modern with direct read-out from the centre circular dial which has the shutter speed settings. This rotates and when it comes to rest speeds are set opposite the fixed aperture scale. ISO is set in a little window, but at first it isn't easy to spot how to set it. It is touch sensitive and one simply places a finger on the background near the window and keeping the finger in contact simply drag until the required ISO appears.

In the centre of the dial is a viewing/aiming window (which changes to an invercone for incident readings) and at the bottom of the meter is a little lever that swings. Drag this and it produces a zoom effect in the window. For this to work, though, the phone's camera must be capable of touch zoom. So a sort of variable spot facility, albeit not to the small reading angle of a true spotmeter, such as my Pentax V. More of a selective area reading, and which could still be a useful, if limited, feature.

And there's more, as Frank Carson used to say. Top right is a little button with "I" and "R" positions. As a photographer, you will know that these stand for incident and reflected light. In the days before TTL metering, and when I shot slide material, I would always use my meters in incident light mode, and it is this feature of this app that has me puzzled. The meter takes its reading through the phone's camera lens and this is fine for reflected light, but without the obligatory white incident dome or slide, how on earth can it carry out a proper incident light reading? I suspect all the software does is introduce an electronic white filter of the same density as the average incident dome. But as these domes read light reaching the subject over a half hemisphere, and thus take into account all light reaching the subject, the camera app can't possibly do this.

I shall have to get my old meters out and check this app out against them, but for the moment I can say that switching between the two settings does produce different readings!

Despite its potential short coming when used in incident mode, this can be a very useful app indeed.

That's interesting and obviously turns your phone/app combo into a pukka incident meter. Checking out my app further, reference is made to the need for a dome, but doesn't offer a source for one from the developer. If required, though, I could tape the translucent slide from one of my normal meters and with a little experimentation/calibration this would work reasonably well. But there again, if I were using slide film (highly unlikely now) I'd fall back on one of my proper meters.